Dry cell



Feb, 29, 1944. H E, LAWSON 2,343,194

DRY CELL FiledNOv. l, 1940 /f-f, L -vf CHROM/ITE 0R Alva GL z/comf Patented Feb. 29, 1944 f DBYCELL Herbert E. Lawson, Chicago, lll., assigner to Burless Battery Company, Chicago, lll.,'a corporation o! Delaware Appueauon November 1, 1940, serial No. 363,824 v s claims. (ci. 13smsi This invention relates to dry cells, and particularly to improvements in the construction of such dry cells whereby deterioration during periods of storage and inactivity is reduced.

It is the object of the invention to provide a dry cell which has improved "shelf-lite and intermittent drain properties. e v

Briefly, the object of the invention is eiected by applying kto the surface of the zinc anode which is exposed to the electrolyte of the dry cell, a compound containing a Cro: radical, in combination with a compound having a' glucoside structure. In accordance with the present invention, it has been discovered that a compound having the CIO: radical. when in association with a glucoside or a 'glucosata is highly effective in inhibiting the corrosion of the zinc anode, which, due to local action or other causes. occurs during periods of inactivity of the dry cell.

The invention will be described in connection with the common cylindrical type of dry cell. The dry cell which is illustrated in the drawing comprises an open-top cylindrical zinc can Il which is the anode. Upon the bottom of the can is disposed a'layerfof electrical insulating material Il,which may be a heat-fusible pitch or wax composition, a resin, or a treated ilbrous material such as paper board or pulp board, which is resistant to the electrolyte of the cell. A carbon rod cathode I2 is disposed substantially centrally of the zinc can I0 and has a metal cap Il upon its upper end. The carbon rod is mechanically separated and electrically insulated from the bottom of the can Il by the insulating layer Il. The carbon rod l2 is surrounded by a moist, compacted mass of depolarizing materialv I I of .example and the invention may be applied to other types oi' primary cells, such as the fiat or plate type, and to cells in which the anode is lof a metal other than zinc, such as magnesium,

aluminum, etc., and also to cells employing depolarizers other than manganese dioxide, such as copper oxide and lead oxide and electrolytes other than that described heretofore, such as the alkali metal sulfatos.

. It is not uncommon for dry cells to remain in storage, in the plant or on the dealers shelf, for

a considerable 'period between the time they are manufactured and the time they are placed in use by the consumer. After they are placed in use. they may be discharged rapidly, or they may i be discharged slowly and only intermittently with relatively long vperiods of inactivity intervening which may be composed of powdered manganese y dioxide ore, carbon or graphite. ammonium chloride, zinc chloride, water and other well-known ingredients. Between the depolarizing body Il and the zinc can III is a substantially solid layer Il of electrolyte, which may be composed of the usual electrolyte substances, such as water. starch, usually in ygelatlnized form, ammonium chloride, zinc chloride, etc. The electrolyte is in A the form of a liquid suspension when initially inserted in the can l0 and becomes solidified by gelatinization of the starch. A top washer Il is arranged in spaced relation` above the depolarizing body Il to form an expansion space l1, and a heat-fusible seal I8,\of wax, pitch, or other suitable material, rests upon washer I8 and forms a seal closure for-the open top of the can III.

The speciilc dry cell described is given by way between periods of use. It is highly important, therefore, that a dry cell does not deteriorate and lose its capacity to deliver electric energy during such periods of inactivity. Unless steps are taken to resist such deterioration, it takes place at an 'appreciable rate, and the dry cell industry has 2,' from the beginning striven to overcome this difilculty. This invention provides an improved '-means for accomplishing the purpose,

' It has been known for along time that chromic acid, or a salt ot 'chromic acid, reduces deterioration of a dry cell during inactivity. This is described in United States Patent No. 1,331,877, dated February 24, 1920. In accordance with the present invention, it has been discovered that the eilectiveness oi a compound containing a CrO.: radical, such as chromic vacid or a salt of chromicacid, is greatly augmented when it is used in association with certain compounds having a glucoside structure. These compounds themselves, in the absence of a compound having a CIO: radical, do not have any appreciable eiiect in inhibiting corrosion 4of the zinc anode during inactivity o i' the cell. Some of them` on the contrary, cause an increase in the corrosion. When they are used in .association with s. CrO: radical. however, they have the property of in `creasing the inhibitingiower oi the CrOs-.radical to a remarkable degree, both before and after the cell is initially placed in use. The combination, however, does not interfere with the free delivery of energy while the cell is in service.

The compounds containing a CrOa radical which may be used are chromic acid, and its salts, such as the alkali metal (including ammonium), chromates and dichromates, etc. These compounds are water-soluble. The coml the dry cell in many ways.

pounds having a glucoside structure which are suitable are beta glucoside,

in` which R represents a 26 atom carbon cha-in.

Sodium glucosate:` l

. Sodium chrome glu-cosate:

Acid chrome glucosate: y

Sodium pyro glucosate:l

o l noR-onon-onon-on-onoP.o.N.-oH,oH Sodium sulpho glucosate:

Phospho glucosate:

. non.onoH-Cnonln-onmrotcmon Sodium hemiphospho glucosate: K

Some of the above glucosates, namely sodium chrome glucosate and acid chrome glucosate, are described and Adiscussed in an article en- A-tililed Film inhibitors in industrial aqueous systems" by David W. Haering, Journal of Industrial andv Engineering Chemistry, vol. 30, pages 1356-1361.(1938).

Other glucosate compounds may be used, as the substitution products in which potassium or ammonium is substituted for sodium, and other metal substitution products except those of the heavy metals which are electropositive to the anode metal of the dry cell, .that is, those substitution products of metals which are electronegative to the anode metal may be used. The glucosate compound may contain a CrOa radical within itself. For example, when sodium chrome glucosate is used, this compound itself supplies a dichromatejradical. In such case, a separate compound containing a CrO: radical need not Ybe employed. The glucosate compound should not contain a heavy metal whichiselectropositive to zinc, since the presence of such a metal apparentlysets up local couples withthe result that there is considerable zinc corrosion. The term "glucosate compound" as used in the specf lilcation and claims contemplates the above described beta glucoside and the inorganic substitution derivatives thereof except those of a heavy metal whichl is electropositive to the anode metal. When a specific compound is mentioned by name, the compound of the formula set forth heretofore is intended.

The inhibiting compound may be applied to The lglucosate compounds are colloidal substances, and may be added directly to the liquid electrolyte before it is incorporated in the dry cell, and the CrO: radi- Y cal may be incorporated separatelyin the form of chromic acid or a saltof this acid which is adapted to bring the CrO: radical into solution t in the electrolyte and make it available at the vsurface of the zinc anode.

The glucosate .compound and the compound containing the CrOa radical may be mixed together and added in association to the electrolyte before the latter is 'incorporated in the dry cell. Alternatively, the compounds, separately or in association, may be placed upon the top of the depolarizlng body i4 or'the electrolyte Il after 'these have been incorporated in the dry cell can. when they will be absorbed by the depolarizing-=body or electrolyte paste and spread to the surface of the zinc can Il, where it becomes distributed uniformly and protects the entire area of the zinc which` is exposed tothe electrolyte.

As an alternative, the compounds may be`ap plied by rinsing or painting the surface of the zincl anode which is to be exposed to the electrolyte with a suspension of the compounds, either separatelyor in association with each other,` before the cell is assembled, or by dipping the anode momentarily into such a suspension.

In a well-lmow'ntype of dry cell, the electrolyte layer Il is in the form of a lining of bibulouspaper pulp sheet material saturated with electrolyte suspension and arranged against the interior surface of can I0. The inhibiting compounds may be incorporated in such liquid elec trolyte or they may be applied to the paper pulp sheet before or after it is saturated with the electrolyte. v The amount of the compound which should be used is not critical. Only a relatively small amount is required, depending upon the specific compounds used. In a dry cell adapted to heavy Aduty service, suchl as meter readers flashlight general. more is used in cells intended for light.,

intermittent service tha-n in those intended for heavyduty. An excessive quantity should not be used as this will interfere with the proper operation of the cell.

I claim:

l. In 'a dry cell having an electrolyte and an anode from the group consisting of magnesium. aluminum and zinc having a. surface exposed to said electrolyte, means at 'said surface for inhibiting corrosion of said anode during inactivity of `said lcell, which comprises a compound from the group consisting of chromic acid and the Water soluble salts of 'said acid in combination with a'compound from the group consisting of beta glucoside and the colloidal metal glucosates of said glucoside in which the metal is electronegative to the anode metal, said beta glucoside being the compound defined herein of the formula in which R is a 26 atom carbon chain.

2. In a dry cell having an electrolyte and an anode from the group consisting of magnesium.

aluminum and zinc having a surface exposed to said electrolyte, means at said surface for inhibiting corrosion of said anode during inactivity of said cell, which comprises a colloidal metal glucosate of vbeta glucoside in which the metal is electronegative to the anode metal, said beta glucoside being the compound dened herein hav.-

f ing the formula v --O CHO R-CHOHTCHOELELCHOLLCHIOH said glucosate containing a radical from the.

in which R is a 26 atom carbon chain at the surface of said anode which is exposed to said electrolyte.

4. In a dry cell having a chloride-containing electrolyte and an anode of a metal from the group consisting of magnesium, aluminum and zinc exposed to said electrolyte, means for inhibiting corrosion oi said anode during inactivity of said cell, which comprises the acid chrom glu cosate dened herein of the formula in which R is a 26 atom chain at the surface of said anode which is exposed to said electrolyte. 5. In a dry cell having a chloride-containing electrolyte and an anode of a metal from the group consisting of magnesium, aluminum and zinc having a surface exposed to said electrolyte. means at said surface for inhibiting corrosion of said anode during inactivity of said cell, which comprises a compound from the group consisting of chromic acid and the water'solublesalts of chromic acid in combination with the sodium glu cosate defined herein of the frmula v in which R is a 26 atom carbon chain.

HERBERT E. LAWSON.

CERTIFICATE OF CORRECTION.

.rasant No. 2,515,191

f Febr-nary 29,19%. I

HERBERT E. Lawson.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring. correction es follows: Page 1, first column, lines 1l and 15, and second column, lines 514., 59, lili, )+6 and '51, page 2, .first column, lines 51| and 58,. and second column, lines 1, li. and 7, for "Gro" read --ehromate or dichromate; and that vthe said Letters Patent should be read with this correction therein that the same may con-- I 'form to the record of the case 1n the Patent Office.

r vsignes and sealed this 25rd day of may, A. D. 19141;.

(Seal) Leslie Frazer Acting Commissioner of Patents.v

aluminum and zinc having a surface exposed to said electrolyte, means at said surface for inhibiting corrosion of said anode during inactivity of said cell, which comprises a colloidal metal glucosate of vbeta glucoside in which the metal is electronegative to the anode metal, said beta glucoside being the compound dened herein hav.-

f ing the formula v --O CHO R-CHOHTCHOELELCHOLLCHIOH said glucosate containing a radical from the.

in which R is a 26 atom carbon chain at the surface of said anode which is exposed to said electrolyte.

4. In a dry cell having a chloride-containing electrolyte and an anode of a metal from the group consisting of magnesium, aluminum and zinc exposed to said electrolyte, means for inhibiting corrosion oi said anode during inactivity of said cell, which comprises the acid chrom glu cosate dened herein of the formula in which R is a 26 atom chain at the surface of said anode which is exposed to said electrolyte. 5. In a dry cell having a chloride-containing electrolyte and an anode of a metal from the group consisting of magnesium, aluminum and zinc having a surface exposed to said electrolyte. means at said surface for inhibiting corrosion of said anode during inactivity of said cell, which comprises a compound from the group consisting of chromic acid and the water'solublesalts of chromic acid in combination with the sodium glu cosate defined herein of the frmula v in which R is a 26 atom carbon chain.

HERBERT E. LAWSON.

CERTIFICATE OF CORRECTION.

.rasant No. 2,515,191

f Febr-nary 29,19%. I

HERBERT E. Lawson.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring. correction es follows: Page 1, first column, lines 1l and 15, and second column, lines 514., 59, lili, )+6 and '51, page 2, .first column, lines 51| and 58,. and second column, lines 1, li. and 7, for "Gro" read --ehromate or dichromate; and that vthe said Letters Patent should be read with this correction therein that the same may con-- I 'form to the record of the case 1n the Patent Office.

r vsignes and sealed this 25rd day of may, A. D. 19141;.

(Seal) Leslie Frazer Acting Commissioner of Patents.v 

